Liquid Crystal Devices

Abstract

A liquid crystal device including a layer of liquid crystal material, and provided on one side of the liquid crystal material layer an array of conductors for generating electric fields therebetween to change the molecular orientation of pixel portions of the layer of liquid crystal material, wherein each pixel portion of the liquid crystal material layer is associated with a respective group of conductors distributed over the respective pixel area for the application of voltages across distances smaller than the pixel dimensions, wherein the conductors and the spacing therebetween within each group are sufficiently small with respect to the thickness of the liquid crystal material layer that each group can be used to generate an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform across the whole area of the respective pixel portion.

1 . A liquid crystal device including a layer of liquid crystal material, and provided on one side of the liquid crystal material layer an array of conductors for generating electric fields therebetween to change the molecular orientation of pixel portions of the layer of liquid crystal material, wherein each pixel portion of the liquid crystal material layer is associated with a respective group of conductors distributed over the respective pixel area for the application of voltages across distances smaller than the pixel dimensions, wherein the conductors and the spacing therebetween within each group are sufficiently small with respect to the thickness of the liquid crystal material layer that each group can be used to generate an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform across the whole area of the respective pixel portion.  
   
   
       2 . A liquid crystal device including a layer of liquid crystal material, and provided on one side of the liquid crystal material layer an array of conductors for generating electric fields therebetween to change the molecular orientation of pixel portions of the layer of liquid crystal material, wherein each pixel portion of the liquid crystal material layer is associated with a respective group of conductors distributed over the respective pixel area for the application of voltages across distances smaller than the pixel dimensions, wherein the thickness of the liquid crystal material layer is at least five times greater than the pitch of the conductors within each group.  
   
   
       3 . A liquid crystal device according to  claim 1 , wherein each group of conductors comprises an array of parallel longitudinal conductors.  
   
   
       4 . A liquid crystal device according to  claim 3 , wherein the conductors comprise the digits of a pair of interdigitated electrodes  
   
   
       5 . A liquid crystal device according to  claim 1 , wherein each group of conductors is a two-dimensional array of separate conductors.  
   
   
       6 . A display system including a liquid crystal device according to  claim 1 .  
   
   
       7 . An optical switching system including a liquid crystal device according to  claim 1 .  
   
   
       8 . A method of controlling the optical properties of a pixel portion of the liquid crystal material layer of the device according to  claim 1 , the method including applying voltages across conductors within the associated group so as to generate in said pixel portion of the liquid crystal material layer an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform across the whole area of the pixel portion.  
   
   
       9 . A liquid crystal display device including on one side of a layer of liquid crystal material at least one pair of interdigitated electrodes, wherein the width of the digits and the spacing between the digits is sufficiently small with respect to the thickness of the liquid crystal material layer that an electric field can be generated that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform over both the digits and the spaces between the digits.  
   
   
       10 . A method of operating a liquid crystal display device according to  claim 9 , including the step of applying a potential difference across the electrodes so as to generate in the liquid crystal material layer an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform over both the digits and the spaces between the digits.  
   
   
       11 . A liquid crystal display device including on one side of the liquid crystal layer at least one pair of conductors spaced in an X-direction, wherein the spacing between the conductors is sufficiently small with respect to the thickness of the liquid crystal material layer that an electric field can be generated that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform over the area directly between the electrodes and an extension of that area in the Y-direction.  
   
   
       12 . A method of operating a liquid crystal display device according to  claim 11 , including the step of applying a potential difference across the conductors so as to generate in the liquid crystal material layer an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform over the area directly between the electrodes and an extension of that area in the Y-direction.